How often does one annual festival stage a fund-raiser for another festival in a different town?

That is what will happen Thursday, July 28, when the kickoff party for Petaluma’s Rivertown Revival doubles as a benefit for the the Handcar Regatta, to be held Sept. 25 in Santa Rosa’s Railroad Square.

The Rivertown Revival Kick-Off Party runs from 7 to 11 p.m. Thursday at the Phoenix Theater, 201 Washington St., Petaluma.

The musical lineup for the evening includes the Jug Dealers, the David Luning Band, Three-Legged Sister, Crux, The Easy Leaves and Katie Phillips, plus Brandon the Clown.

Admission: $8; $5 for Rivertown Revival volunteers. Age 21 and over. Lagunitas beer will be served.

Information: (707) 326-5274, www.rivertownrevival.com.

The Rivertown Revival festival itself, including boat races, live music and more, will be held 11 a.m.-7 p.m. Saturday, July 30, at Petaluma River Heritage Center, McNear Peninsula. Enter Steamer Landing Park from downtown at the South end of Copeland Street, at D Street.

Admission: Free. Donations welcome.

There also be a Rivertown Revival Afterparty, with live music by El Radio Fantastique, Brothers Horse, Malarkey and Shovelman, at 8 p.m. Saturday, July 30, at the Mystic Theatre, 23 Petaluma Blvd. N., Petaluma.

Admission: $21 in advance; $15 at the door. Age 21 and older only.

Information:  (707) 765-2121, www.mystictheatre.com.